After playing with the same configuration many times, me and my friend suddenly cannot play together.
This is because the game generates different map for each player upon entering the game/leaving the whale. It lis like we are in the same game, but playing separate maps.
According to modthespire log, the map is generated for each player after we leave the whale.
Does anyone know a fix? Even reinstalling game and mods has not helped so far...

Edit: Not even waiting for several months and reinstalling the steam client has helped. :(